At some point in our lives, most of us have to make decisions about our health care. Some of these decisions are relatively simple and straightforward. For example, you probably don't spend much time pondering whether or not to get a flu shot, and you probably would follow your doctor's advice without a second thought if he or she recommended you take an antibiotic for a urinary tract infection or have a biopsy for a suspected skin cancer. None of these decisions would require much reflection or soul-searching.

However, some decisions about health care are neither simple nor straightforward. For women with stage IV breast cancer, deciding whether or not to undergo a combination of mastectomy, chemotherapy, radiation therapy, and bone marrow transplantation may be extremely difficult and stressful. For men with a new diagnosis of prostate cancer, deciding whether to have surgery and risk impotence and/or urinary incontinence is neither simple nor straightforward.

If decision making about our own health care is challenging when we can decide for ourselves, it's bound to be much more so if we try to plan ahead and make decisions today that can be used to guide our health care if we lose our decision-making ability years or decades in the future. If you have to decide today whether to begin dialysis tomorrow, at least you can discuss the pros and cons with your physician and make a decision based on information about your current overall health, the medical condition that has caused kidney failure, the expected benefits and harms, your prognosis, and so forth.